[A case of oral squamous cell carcinoma responding to S-1].

A 76-year-old patient with oral squamous cell carcinoma was treated by chemotherapy with S-1. S-1 (100 mg/body/day) was orally administered for 4 weeks followed by a 2-week rest period as one course. The primary lesion markedly decreased at 7 days after the beginning of S-1 treatment, and disappeared after one course of S-1. After two courses, the primary lesion was assessed to show a complete response (CR),and no tumor cells were identified as a result of biopsy. In addition, the value of tumor marker SCC decreased from 2.13 ng/mL before treatment to 0.68 ng/mL after two courses of S-1. Although the patient is still taking UFT, she is well with no signs of recurrence 50 months from the initial treatment.